The present invention relates generally to bags designed for dispensing medical fluids, and particularly to an improved dialysis bag having features for preventing occlusion or flow choke-off of the outlet port.
Patients suffering from certain forms of chronic kidney disease are treated with peritoneal dialysis, which can be performed at home. Such treatment involves periodically flushing the peritoneal cavity in the abdomen with a remedial fluid that absorbs unwanted electrolytes, urea, glucose, albumin and other small molecules that are filtered by the kidneys in a healthy individual. Upon flushing the fluid from the peritoneal cavity, the unwanted substances are removed from the body. In this manner, a patient can avoid the inconvenience and relatively more drastic swings in levels of unwanted substances common when conventional dialysis is used.
As part of the home dialysis procedure, a bag of sterilized peritoneal fluid is laid on its side in a horizontal orientation upon a heated surface of a computerized fluid pumping device, exemplified by the Baxter HomeChoice Automated Peritoneal Dialysis (APD) System. Additional supply bags normally connected by a tubing set with the heated bag may also be laid on their sides in close proximity to the pumping device when higher volumes of dialysis fluid are prescribed for treatment. In operation, a bag lies flat upon the heated upper surface of the APD cycler or device. A tubular administrative outlet of the bag is placed in fluid communication with the disposable APD tubing set, and fluid is pumped into the patient according to a pre-selected dosing regimen. It is common for a peritoneal flushing treatment using an APD to last as long as 8 hours. During this treatment, at least one and often several large volume bags of dialysis fluid are used. The volumes of these bags may range between 2000 ml and 6000 ml.
In some cases, it has been found that as the bag empties, an upper film of the bag collapses upon an inlet of the outlet tube, thus blocking further flow of fluid to the patient. The APD system is designed to generate an alarm in such instances, as well as in other situations when fluid flow falls below preset levels. However, due to patient inconvenience and the unwanted interruption in the treatment program, such alarms are to be avoided.